Car smokes white, smells burnt, misfires on cold start

Hi, thank you for your time.
Yesterday I started my car (2006 Hyundai Tucson, engine code: G4GC)
and it cranked over just fine. But after one second it started smoking white, knocking pretty bad and smelled burnt. Unsure of the situation, I shut it of. I put some buckets of hot water under the oil pan, and let it sit. The outside temperature was -7 degrees Celsius/ 19 degrees Fahrenheit. When I restarted the car, it cranked over for about half a minute and then started. It only ran on three cylinders and was smoking white. I then went on a drive to get the temp up and it then ran just fine, even if a little low on RPMs.
I heard that it could be various problems, but have now clue really.
It had european mid grade fuel in it, we usually do 9.000 mile oil changes and are now about 8.500 in. The car has 117.256 miles on it. What could my issue be? I would be very thankful for an answer.

With out any of us seeing the car, that’s going to be the best answer


Ok, not particularly cold, smoked white. Sounds like maybe a fuel injector stuck open… but that is a wild guess.

Is the check engine light on?

If it was running on only 3 cylinders, surely the Check Engine Light must have lit up.
Until you get the Diagnostic Trouble Codes read, nobody here could know where to start with a diagnosis.

There is no check engine light

Thank you all, I will try to get the code scannned, allthough I do not currently have access to a scanner.

Things may well be different in Europe, but in The US many auto parts stores will perform that service for you w/o charge.
Phone some parts stores, and ask if they do that.

I believe this engine uses a timing belt. Was it ever changed? Gates says it should be changed every 60,000 miles.

I’m going to guess someone used water instead of coolant, or not the correct ratio of water to coolant. Temp got down below freezing, water froze in the engine, head gasket was ruined or head was cracked at water jacket. Hopefully that isn’t the case. Does it overheat at all if you keep driving it?

The head gasket is leaking allowing coolant into the cylinder after shut-off. After the engine cools, remove the spark plugs and look into the cylinders with a borescope for coolant.

1 Like

Indeed it uses a timing belt, but it has been changed recently.

The car had a craked radiator hose and apparently too much water is in the system. But it ran at the normal temp and wasn‘t overheating